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Rivas M, Serantes D, Pascovich C, Peña F, Ferreira A, Torterolo P, Benedetto L. Electrophysiological characterization of medial preoptic neurons in lactating rats and its modulation by hypocretin-1. Neurosci Res 2022; 184:19-29. [PMID: 36030967 DOI: 10.1016/j.neures.2022.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/08/2022] [Accepted: 08/21/2022] [Indexed: 11/30/2022]
Abstract
The medial preoptic area (mPOA) undergoes through neuroanatomical changes across the postpartum period, during which its neurons play a critical role in the regulation of maternal behavior. In addition, this area is also crucial for sleep-wake regulation. We have previously shown that hypocretins (HCRT) within the mPOA facilitate active maternal behaviors in postpartum rats, while the blockade of endogenous HCRT in this area promotes nursing and sleep. To explore the mechanisms behind these HCRT actions, we aimed to evaluate the effects of juxta-cellular HCRT-1 administration on mPOA neurons in urethane-anesthetized postpartum and virgin female rats. We recorded mPOA single units and the electroencephalogram (EEG) and applied HCRT-1 juxta-cellular by pressure pulses. Our main results show that the electrophysiological characteristics of the mPOA neurons and their relationship with the EEG of postpartum rats did not differ from virgin rats. Additionally, neurons that respond to HCRT-1 had a slower firing rate than those that did not. In addition, administration of HCRT increased the activity in one group of neurons while decreasing it in another, both in postpartum and virgin rats. The mechanisms by which HCRT modulate functions controlled by the mPOA involve different cell populations.
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Affiliation(s)
- Mayda Rivas
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Diego Serantes
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Claudia Pascovich
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Consciousness and Cognition Laboratory, Department of Psychology, University of Cambridge, Cambridge, UK
| | - Florencia Peña
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Annabel Ferreira
- Sección de Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Pablo Torterolo
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Luciana Benedetto
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
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Kirouac GJ, Li S, Li S. Convergence of monosynaptic inputs from neurons in the brainstem and forebrain on parabrachial neurons that project to the paraventricular nucleus of the thalamus. Brain Struct Funct 2022; 227:2409-2437. [PMID: 35838792 PMCID: PMC9418111 DOI: 10.1007/s00429-022-02534-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/30/2022] [Indexed: 11/28/2022]
Abstract
The paraventricular nucleus of the thalamus (PVT) projects to areas of the forebrain involved in regulating behavior. Homeostatic challenges and salient cues activate the PVT and evidence shows that the PVT regulates appetitive and aversive responses. The brainstem is a source of afferents to the PVT and the present study was done to determine if the lateral parabrachial nucleus (LPB) is a relay for inputs to the PVT. Retrograde tracing experiments with cholera toxin B (CTB) demonstrate that the LPB contains more PVT projecting neurons than other regions of the brainstem including the catecholamine cell groups. The hypothesis that the LPB is a relay for signals to the PVT was assessed using an intersectional monosynaptic rabies tracing approach. Sources of inputs to LPB included the reticular formation; periaqueductal gray (PAG); nucleus cuneiformis; and superior and inferior colliculi. Distinctive clusters of input cells to LPB-PVT projecting neurons were also found in the dorsolateral bed nucleus of the stria terminalis (BSTDL) and the lateral central nucleus of the amygdala (CeL). Anterograde viral tracing demonstrates that LPB-PVT neurons densely innervate all regions of the PVT in addition to providing collateral innervation to the preoptic area, lateral hypothalamus, zona incerta and PAG but not the BSTDL and CeL. The paper discusses the anatomical evidence that suggests that the PVT is part of a network of interconnected neurons involved in arousal, homeostasis, and the regulation of behavioral states with forebrain regions potentially providing descending modulation or gating of signals relayed from the LPB to the PVT.
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Affiliation(s)
- Gilbert J Kirouac
- Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Avenue, Winnipeg, MB, R3E 0W2, Canada. .,Departments of Psychiatry and Human Anatomy and Cell Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, R3E 0W2, Canada.
| | - Sa Li
- Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Avenue, Winnipeg, MB, R3E 0W2, Canada
| | - Shuanghong Li
- Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Avenue, Winnipeg, MB, R3E 0W2, Canada
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Sound disrupts sleep-associated brain oscillations in rodents in a meaning-dependent manner. Sci Rep 2022; 12:6051. [PMID: 35410339 PMCID: PMC9001723 DOI: 10.1038/s41598-022-09457-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 03/22/2022] [Indexed: 11/08/2022] Open
Abstract
AbstractSleep is essential but places animals at risk. Filtering acoustic information according to its relevance, a process generally known as sensory gating, is crucial during sleep to ensure a balance between rest and danger detection. The mechanisms of this sensory gating and its specificity are not understood. Here, we tested the effect that sounds of different meaning have on sleep-associated ongoing oscillations. We recorded EEG and EMG from mice during REM and NREM sleep while presenting sounds with or without behavioural relevance. We found that sound presentation per se, in the form of a neutral sound, elicited a weak or no change in the power of sleep-state-dependent EEG during REM and NREM sleep. In contrast, the presentation of a sound previously conditioned in an aversive task, elicited a clear and fast decrease in the EEG power during both sleep phases, suggesting a transition to lighter sleep without awakening. The observed changes generally weakened over training days and were not present in animals that failed to learn. Interestingly, the effect could be generalized to unfamiliar neutral sounds if presented following conditioned training, an effect that depended on sleep phase and sound type. The data demonstrate that sounds are differentially gated during sleep depending on their meaning and that this process is reflected in disruption of sleep-associated brain oscillations without behavioural arousal.
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Hypocretin (orexin) immunoreactivity in the feline midbrain: Relevance for the generation of wakefulness. J Chem Neuroanat 2020; 105:101769. [PMID: 32145304 DOI: 10.1016/j.jchemneu.2020.101769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 01/08/2023]
Abstract
Hypocretins (Hcrt) 1 and 2 are two neuropeptides synthesized from neurons that are located in the perifornical area of the lateral hypothalamus. These neurons project diffusely throughout the central nervous system, and have been implicated in the generation and maintenance of wakefulness, as well as in critical physiological processes that occur during this behavioral state, such as motivation. The hypocretinergic projections towards the feline midbrain have not been studied before. Therefore, the aim of the present study was to analyze their relationship to the midbrain neurons, that are critically involved in the control of sleep and wakefulness. With this purpose, we examined the distribution of Hcrt1-positive fibers in the midbrain and pontomesencephalic area of the domestic cat (Felis catus), and their relationship with catecholaminergic and cholinergic neurons by means of single and double immunohistochemistry. Hcrtergic axons with distinctive varicosities and buttons were heterogeneously distributed, exhibiting different densities in distinct regions of the midbrain. High Hcrtergic fiber densities were observed in the periaqueductal gray, interpeduncular nucleus, locus coeruleus and cholinergic mesopontine regions. In addition, we studied in detail the Hcrtergic projection towards the dopaminergic nuclei of the midbrain. While very few Hcrt + fibers were observed in the substantia nigra pars compacta, the highest density of Hcrtergic fibers was found in the dopaminergic ventral periaqueductal gray area (also called A10dc area); appositions between Hcrtergic terminals and dopaminergic somata and dendrites were observed within this area. Because this dopaminergic area has been involved in the control of wakefulness, the present anatomical data provides relevant support about the role of the Hcrtergic system in the generation of this behavioral state.
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Liu Y, Zhang G, Yu H, Li H, Wei J, Xiao Z. Robust and Intensity-Dependent Synaptic Inhibition Underlies the Generation of Non-monotonic Neurons in the Mouse Inferior Colliculus. Front Cell Neurosci 2019; 13:131. [PMID: 31024260 PMCID: PMC6460966 DOI: 10.3389/fncel.2019.00131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 03/15/2019] [Indexed: 11/28/2022] Open
Abstract
Intensity and frequency are the two main properties of sound. The non-monotonic neurons in the auditory system are thought to represent sound intensity. The central nucleus of the inferior colliculus (ICC), as an important information integration nucleus of the auditory system, is also involved in the processing of intensity encoding. Although previous researchers have hinted at the importance of inhibitory effects on the formation of non-monotonic neurons, the specific underlying synaptic mechanisms in the ICC are still unclear. Therefore, we applied the in vivo whole-cell voltage-clamp technique to record the excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) in the ICC neurons, and compared the effects of excitation and inhibition on the membrane potential outputs. We found that non-monotonic neuron responses could not only be inherited from the lower nucleus but also be created in the ICC. By integrating with a relatively weak IPSC, approximately 35% of the monotonic excitatory inputs remained in the ICC. In the remaining cases, monotonic excitatory inputs were reshaped into non-monotonic outputs by the dominating inhibition at high intensity, which also enhanced the non-monotonic nature of the non-monotonic excitatory inputs.
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Affiliation(s)
- Yun Liu
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Guodong Zhang
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Haipeng Yu
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - He Li
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Jinxing Wei
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
| | - Zhongju Xiao
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Key Laboratory of Psychiatric Disorders of Guangdong Province, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Key Laboratory of Mental Health of the Ministry of Education, Guangzhou, China
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Costa A, Castro-Zaballa S, Lagos P, Chase MH, Torterolo P. Distribution of MCH-containing fibers in the feline brainstem: Relevance for REM sleep regulation. Peptides 2018; 104:50-61. [PMID: 29680268 DOI: 10.1016/j.peptides.2018.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/15/2018] [Accepted: 04/09/2018] [Indexed: 11/20/2022]
Abstract
Neurons that utilize melanin-concentrating hormone (MCH) as a neuromodulator are localized in the postero-lateral hypothalamus and incerto-hypothalamic area. These neurons project diffusely throughout the central nervous system and have been implicated in critical physiological processes, such as sleep. Unlike rodents, in the order carnivora as well as in humans, MCH exerts its biological functions through two receptors: MCHR-1 and MCHR-2. Hence, the cat is an optimal animal to model MCHergic functions in humans. In the present study, we examined the distribution of MCH-positive fibers in the brainstem of the cat. MCHergic axons with distinctive varicosities and boutons were heterogeneously distributed, exhibiting different densities in distinct regions of the brainstem. High density of MCHergic fibers was found in the dorsal raphe nucleus, the laterodorsal tegmental nucleus, the periaqueductal gray, the pendunculopontine tegmental nucleus, the locus coeruleus and the prepositus hypoglossi. Because these areas are involved in the control of REM sleep, the present anatomical data support the role of this neuropeptidergic system in the control of this behavioral state.
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Affiliation(s)
- Alicia Costa
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Uruguay
| | | | - Patricia Lagos
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Uruguay
| | - Michael H Chase
- WebSciences International and UCLA School of Medicine, Los Angeles, USA
| | - Pablo Torterolo
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Uruguay.
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Devera A, Pascovich C, Lagos P, Falconi A, Sampogna S, Chase MH, Torterolo P. Melanin-concentrating hormone (MCH) modulates the activity of dorsal raphe neurons. Brain Res 2015; 1598:114-28. [DOI: 10.1016/j.brainres.2014.12.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 12/09/2014] [Accepted: 12/13/2014] [Indexed: 12/27/2022]
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